A Daily Mail news report explores the symptoms of sleep paralysis, the risk factors for this condition, and the scientific research conducted to study this phenomenon.
It is assumed that this paralysis mechanism is in place to stop us acting out our dreams, based on rare cases where the paralysis fails – and patients physically act out the contents of their dreams.
A team of Japanese researchers were recently able to induce episodes of sleep paralysis by systematically depriving participants of REM sleep.
They found that if they interrupted enough periods of REM, the sleepers would eventually enter sudden-onset REM (SOREM), which is where one falls straight into REM sleep from waking, bypassing the other sleep stages (this is indicated by the dotted line in the figure).
It was found that following these SOREM periods, participants were more likely to have an episode of sleep paralysis – backing up previous studies showing that disrupted sleep increases the risk.
These studies also tell us that sleep paralysis is closely tied to REM sleep.
What appears to be happening in sleep paralysis is you wake up and become consciously aware of your surroundings while still in a state of REM sleep, meaning your muscles are paralysed.
It could be said that your mind wakes up but your body doesn’t.